
(FPCore (re im base) :precision binary64 (/ (+ (* (log (sqrt (+ (* re re) (* im im)))) (log base)) (* (atan2 im re) 0.0)) (+ (* (log base) (log base)) (* 0.0 0.0))))
double code(double re, double im, double base) {
return ((log(sqrt(((re * re) + (im * im)))) * log(base)) + (atan2(im, re) * 0.0)) / ((log(base) * log(base)) + (0.0 * 0.0));
}
real(8) function code(re, im, base)
real(8), intent (in) :: re
real(8), intent (in) :: im
real(8), intent (in) :: base
code = ((log(sqrt(((re * re) + (im * im)))) * log(base)) + (atan2(im, re) * 0.0d0)) / ((log(base) * log(base)) + (0.0d0 * 0.0d0))
end function
public static double code(double re, double im, double base) {
return ((Math.log(Math.sqrt(((re * re) + (im * im)))) * Math.log(base)) + (Math.atan2(im, re) * 0.0)) / ((Math.log(base) * Math.log(base)) + (0.0 * 0.0));
}
def code(re, im, base): return ((math.log(math.sqrt(((re * re) + (im * im)))) * math.log(base)) + (math.atan2(im, re) * 0.0)) / ((math.log(base) * math.log(base)) + (0.0 * 0.0))
function code(re, im, base) return Float64(Float64(Float64(log(sqrt(Float64(Float64(re * re) + Float64(im * im)))) * log(base)) + Float64(atan(im, re) * 0.0)) / Float64(Float64(log(base) * log(base)) + Float64(0.0 * 0.0))) end
function tmp = code(re, im, base) tmp = ((log(sqrt(((re * re) + (im * im)))) * log(base)) + (atan2(im, re) * 0.0)) / ((log(base) * log(base)) + (0.0 * 0.0)); end
code[re_, im_, base_] := N[(N[(N[(N[Log[N[Sqrt[N[(N[(re * re), $MachinePrecision] + N[(im * im), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] * N[Log[base], $MachinePrecision]), $MachinePrecision] + N[(N[ArcTan[im / re], $MachinePrecision] * 0.0), $MachinePrecision]), $MachinePrecision] / N[(N[(N[Log[base], $MachinePrecision] * N[Log[base], $MachinePrecision]), $MachinePrecision] + N[(0.0 * 0.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\log \left(\sqrt{re \cdot re + im \cdot im}\right) \cdot \log base + \tan^{-1}_* \frac{im}{re} \cdot 0}{\log base \cdot \log base + 0 \cdot 0}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 3 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (re im base) :precision binary64 (/ (+ (* (log (sqrt (+ (* re re) (* im im)))) (log base)) (* (atan2 im re) 0.0)) (+ (* (log base) (log base)) (* 0.0 0.0))))
double code(double re, double im, double base) {
return ((log(sqrt(((re * re) + (im * im)))) * log(base)) + (atan2(im, re) * 0.0)) / ((log(base) * log(base)) + (0.0 * 0.0));
}
real(8) function code(re, im, base)
real(8), intent (in) :: re
real(8), intent (in) :: im
real(8), intent (in) :: base
code = ((log(sqrt(((re * re) + (im * im)))) * log(base)) + (atan2(im, re) * 0.0d0)) / ((log(base) * log(base)) + (0.0d0 * 0.0d0))
end function
public static double code(double re, double im, double base) {
return ((Math.log(Math.sqrt(((re * re) + (im * im)))) * Math.log(base)) + (Math.atan2(im, re) * 0.0)) / ((Math.log(base) * Math.log(base)) + (0.0 * 0.0));
}
def code(re, im, base): return ((math.log(math.sqrt(((re * re) + (im * im)))) * math.log(base)) + (math.atan2(im, re) * 0.0)) / ((math.log(base) * math.log(base)) + (0.0 * 0.0))
function code(re, im, base) return Float64(Float64(Float64(log(sqrt(Float64(Float64(re * re) + Float64(im * im)))) * log(base)) + Float64(atan(im, re) * 0.0)) / Float64(Float64(log(base) * log(base)) + Float64(0.0 * 0.0))) end
function tmp = code(re, im, base) tmp = ((log(sqrt(((re * re) + (im * im)))) * log(base)) + (atan2(im, re) * 0.0)) / ((log(base) * log(base)) + (0.0 * 0.0)); end
code[re_, im_, base_] := N[(N[(N[(N[Log[N[Sqrt[N[(N[(re * re), $MachinePrecision] + N[(im * im), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] * N[Log[base], $MachinePrecision]), $MachinePrecision] + N[(N[ArcTan[im / re], $MachinePrecision] * 0.0), $MachinePrecision]), $MachinePrecision] / N[(N[(N[Log[base], $MachinePrecision] * N[Log[base], $MachinePrecision]), $MachinePrecision] + N[(0.0 * 0.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\log \left(\sqrt{re \cdot re + im \cdot im}\right) \cdot \log base + \tan^{-1}_* \frac{im}{re} \cdot 0}{\log base \cdot \log base + 0 \cdot 0}
\end{array}
(FPCore (re im base) :precision binary64 (/ (log (hypot re im)) (log base)))
double code(double re, double im, double base) {
return log(hypot(re, im)) / log(base);
}
public static double code(double re, double im, double base) {
return Math.log(Math.hypot(re, im)) / Math.log(base);
}
def code(re, im, base): return math.log(math.hypot(re, im)) / math.log(base)
function code(re, im, base) return Float64(log(hypot(re, im)) / log(base)) end
function tmp = code(re, im, base) tmp = log(hypot(re, im)) / log(base); end
code[re_, im_, base_] := N[(N[Log[N[Sqrt[re ^ 2 + im ^ 2], $MachinePrecision]], $MachinePrecision] / N[Log[base], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\log \left(\mathsf{hypot}\left(re, im\right)\right)}{\log base}
\end{array}
Initial program 45.9%
mul0-rgt45.9%
+-rgt-identity45.9%
metadata-eval45.9%
+-rgt-identity45.9%
times-frac46.0%
*-inverses46.0%
*-rgt-identity46.0%
hypot-def99.4%
Simplified99.4%
Final simplification99.4%
(FPCore (re im base) :precision binary64 (if (<= re -4.9e-45) (/ (log (- re)) (log base)) (/ (log im) (log base))))
double code(double re, double im, double base) {
double tmp;
if (re <= -4.9e-45) {
tmp = log(-re) / log(base);
} else {
tmp = log(im) / log(base);
}
return tmp;
}
real(8) function code(re, im, base)
real(8), intent (in) :: re
real(8), intent (in) :: im
real(8), intent (in) :: base
real(8) :: tmp
if (re <= (-4.9d-45)) then
tmp = log(-re) / log(base)
else
tmp = log(im) / log(base)
end if
code = tmp
end function
public static double code(double re, double im, double base) {
double tmp;
if (re <= -4.9e-45) {
tmp = Math.log(-re) / Math.log(base);
} else {
tmp = Math.log(im) / Math.log(base);
}
return tmp;
}
def code(re, im, base): tmp = 0 if re <= -4.9e-45: tmp = math.log(-re) / math.log(base) else: tmp = math.log(im) / math.log(base) return tmp
function code(re, im, base) tmp = 0.0 if (re <= -4.9e-45) tmp = Float64(log(Float64(-re)) / log(base)); else tmp = Float64(log(im) / log(base)); end return tmp end
function tmp_2 = code(re, im, base) tmp = 0.0; if (re <= -4.9e-45) tmp = log(-re) / log(base); else tmp = log(im) / log(base); end tmp_2 = tmp; end
code[re_, im_, base_] := If[LessEqual[re, -4.9e-45], N[(N[Log[(-re)], $MachinePrecision] / N[Log[base], $MachinePrecision]), $MachinePrecision], N[(N[Log[im], $MachinePrecision] / N[Log[base], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;re \leq -4.9 \cdot 10^{-45}:\\
\;\;\;\;\frac{\log \left(-re\right)}{\log base}\\
\mathbf{else}:\\
\;\;\;\;\frac{\log im}{\log base}\\
\end{array}
\end{array}
if re < -4.8999999999999998e-45Initial program 37.1%
mul0-rgt37.1%
+-rgt-identity37.1%
metadata-eval37.1%
+-rgt-identity37.1%
times-frac37.1%
*-inverses37.1%
*-rgt-identity37.1%
hypot-def99.4%
Simplified99.4%
clear-num99.3%
inv-pow99.3%
Applied egg-rr99.3%
unpow-199.3%
div-inv99.3%
associate-/r*99.3%
Applied egg-rr99.3%
Taylor expanded in re around -inf 76.5%
expm1-log1p-u58.6%
expm1-udef58.3%
associate-/l/58.3%
associate-/r*58.4%
frac-2neg58.4%
metadata-eval58.4%
remove-double-div58.4%
neg-log58.4%
clear-num58.4%
div-inv58.4%
metadata-eval58.4%
Applied egg-rr58.4%
expm1-def58.6%
expm1-log1p76.6%
*-commutative76.6%
mul-1-neg76.6%
Simplified76.6%
if -4.8999999999999998e-45 < re Initial program 49.1%
mul0-rgt49.1%
+-rgt-identity49.1%
metadata-eval49.1%
+-rgt-identity49.1%
times-frac49.2%
*-inverses49.2%
*-rgt-identity49.2%
hypot-def99.4%
Simplified99.4%
Taylor expanded in re around 0 29.0%
Final simplification41.6%
(FPCore (re im base) :precision binary64 (/ (log im) (log base)))
double code(double re, double im, double base) {
return log(im) / log(base);
}
real(8) function code(re, im, base)
real(8), intent (in) :: re
real(8), intent (in) :: im
real(8), intent (in) :: base
code = log(im) / log(base)
end function
public static double code(double re, double im, double base) {
return Math.log(im) / Math.log(base);
}
def code(re, im, base): return math.log(im) / math.log(base)
function code(re, im, base) return Float64(log(im) / log(base)) end
function tmp = code(re, im, base) tmp = log(im) / log(base); end
code[re_, im_, base_] := N[(N[Log[im], $MachinePrecision] / N[Log[base], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\log im}{\log base}
\end{array}
Initial program 45.9%
mul0-rgt45.9%
+-rgt-identity45.9%
metadata-eval45.9%
+-rgt-identity45.9%
times-frac46.0%
*-inverses46.0%
*-rgt-identity46.0%
hypot-def99.4%
Simplified99.4%
Taylor expanded in re around 0 25.6%
Final simplification25.6%
herbie shell --seed 2023187
(FPCore (re im base)
:name "math.log/2 on complex, real part"
:precision binary64
(/ (+ (* (log (sqrt (+ (* re re) (* im im)))) (log base)) (* (atan2 im re) 0.0)) (+ (* (log base) (log base)) (* 0.0 0.0))))